This invention relates generally to devices for penetrating the lumen of a blood vessel of a patient and more particularly to improvements in catheter devices for coupling an intravenous fluid supply to a blood vessel, and for measuring central venous pressures.
Antiquated catheter devices formed from lengths of fragile glass, stainless steel, or plastic materials have created several problems. For example, continued use of plastic catheter devices in the body of a patient may cause reactions which lead to infections. Thus, medical practice requires that such plastic catheter devices be replaced often. Stainless steel devices avoided such adverse reactions, but were generally inflexible, thereby increasing the possibility of accidentally perforating the patient's blood vessels. To overcome these problems, sturdier and more flexible catheter devices formed of wire-wound coils have been proposed. Such helically wound cannular devices have enabled the construction of relatively long catheters which combine flexibility with the ability to transmit rotational torque so that the distal portion of the catheter which is disposed within a vessel of a patient can be guided by manipulation of the externally disposed proximal portion. Such maneuverability has permitted the insertion of catheter devices through vessels having curves of relatively short radii, while reducing the risk of damage to the wall of the vessel.
One helical coil spring guide which has been used in connection with the insertion of a catheter into the vessels of a body is shown in U.S. Pat. No. 3,973,556, which issued to Fleischhacker et al. Fleischhacker et al. teach a coil spring guide having a helically wound coil spring portion which, in operation, is disposed around a wire core. The wire core, which may be of stainless steel, is disposed near the longitudinal central axis of the coil spring, and is welded to the distal end of the coil spring. Another prior art spring guide and catheter combination is taught in U.S. Pat. No. 3,757,768 which issued to W. M. Kline. Kline teaches a manipulable unitary spring guide and catheter which is formed from a continuous, helically wound metal spring, and has a preconfigured wire stylette which aids in the guidance or positioning of the distal portion of the catheter. Thus, in addition to having a core wire which should preferably be removed to permit sufficient capacity within the lumen of the catheter for proper infusion of a fluid, or to permit the taking of pressure measurements, percutaneous access to the lumen of a vein or other vessel of a patient is achieved by the use of a sharpened needle through which the guide catheter is inserted, and which is thereafter immediately removed.
It is, therefore, an object of this invention to provide a flexible catheter which does not require the removal of a guide wire.
It is a further object of this invention to provide a catheter which can penetrate into, and remain for extended periods within, the lumen of a vessel of a patient's body without adversely interacting with the fluids therein and increasing the risk of infection.
It is a still further object of this invention to provide a catheter which is flexible and will not kink so as to minimize the possibility of accidentally perforating the wall of a patient's blood vessel or heart.
It is another object of this invention to provide a device for coupling a supply of intravenous fluid to a vessel of a patient's body almost immediately upon venipuncture.